What do you think will happen?

What do you think will happen if I click on S? Will I teach my spam filter that it was right in catching this mail, or will I have the email delivered to me? (I suppose the lack of an “N” option is disabled by the administrator, but then does it really need to be in the caption? Never figured out what the red markers were for.)

My point here is: the actual, real-case usability of a web app is complex, fiddly, and can break down easily. Using short-hand for controls along with captions to explain what the short-hand means — this isn’t a sensible trade-off.